DIETARY SUPPLEMENTATION FOR IMPROVEMENT OF GASTROINTESTINAL SYMPTOMS AND QUALITY OF LIFE IN INDIVIDUALS WITH KIDNEY FAILURE

Abstract

Fiber has the potential to restore gut microbiota balance and thus suppress the production of uremic molecules in adults with chronic kidney disease (CKD). A randomized, double-blind, placebo-control, crossover study was conducted with adults undergoing kidney replacement therapy. Following a 1-week baseline, participants consumed muffins with pea hull fiber (15 g/d) and control muffins daily for 4 weeks in random order, separated by a 4-week. Serum p-cresyl sulfate (PCS), indoxyl sulfate (IS) and trimethylamine N-oxide (TMAO) were analyzed by LC–MS/MS and fecal microbiome profile by 16S rRNA gene amplicon sequencing. Quantitative Polymerase Chain Reaction (qPCR) for taxa of interest was performed. QIIME 2 sample-classifier was used to discover a unique microbiota profile due to pea hull fiber. Of the 18 participants randomized (50 ± 4 y; eGFR 6.6 ± 0.7 ml/min/1.73m2), 13 completed the study. No changes from baseline were observed in serum PCS (3256±505 μmol/L), IS (166 ± 23 μmol/L) or TMAO (96 ± 12 μmol/L), or for the relative quantification of A. muciniphila, F. prausnitzii, Bifidobacterium, and Roseburia, taxa thought to be health enhancing. Taxa that most distinguished the microbiota composition during the pea hull fiber intervention from usual diet periods were enriched Gemmiger, Collinsella and 17 depleted Lactobacillus, Ruminococcus, Coprococcus and Mogibacteriaceae. Microbiota composition was also compared to healthy controls, and three taxa, Peptostreptococcaceae, Faecalibacterium, and Lachnospira, were lower in subjects undergoing kidney replacement therapy, whereas eight taxa, Rikenellaceae, Granulicatella, Oscillospira, Collinsella, Coprobacillus, Eggerthella, Ruminococcus, and Rothia, were higher with kidney replacement therapy. Given the high reporting of reflux in this trial, a phase 1 trial was conducted to determine the safety and efficacy of Lactobacillus delbrueckii fermented soy supplementation on heartburn symptoms. Although quality of life indicators improved, no an acute effect of heartburn symptoms was found. In adults undergoing kidney replacement therapy, added pea hull fiber did not reduce the serum levels of targeted uremic molecules but did alter fecal microbiota composition. Future research in this patient population should explore the efficacy of alternate fiber sources for reducing serum levels of uremic molecules and supplementation for improving gastrointestinal symptoms.